1373620 - <a href="leading-to-error-404" download> navigates

Status: RESOLVED WORKSFORME

(Core :: DOM: Core & HTML, defect, P3)

Description

[PhistucK]

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.86 Safari/537.36

Steps to reproduce:

Go to http://w3c-test.org/submissions/6211/html/semantics/text-level-semantics/the-a-element/a-download-click-404.html


Actual results:

Fails


Expected results:

Succeeds

Basically, I would never expect <a href="leading-to-error-404" download> to navigate.
But if leading-to-error-404 return HTTP status code 404 and its content type is text/html, Firefox navigates to an internal error page.

The other browsers download (and either fail, or download the 404 response).

Comment 1

[PhistucK]

https://github.com/w3c/web-platform-tests/pull/6211

Comment 2

[PhistucK]

Note - not only does it navigate, it navigates to an internal error page even if the server returns a real HTML error response.

Comment 3

[Hsin-Yi Tsai (she/her) [:hsinyi]]

Sec. 4.6.5 Downloading resources[1] says "When a user agent is to handle a resource obtained from a fetch as a download, it should provide the user with a way to save the resource for later use, if a resource is successfully obtained; or otherwise should report any problems downloading the file to the user."

According to this, the current firefox behaviour seems do nothing wrong. Did I miss anything?


[1] https://html.spec.whatwg.org/#downloading-resources

Comment 4

[Simon Pieters [:zcorpan]]

"report any problems" is different from "navigate to an error page". The spec currently allows navigating to an error page if the URL fails to parse.

Comment 5

[Jessica Jong [:jessica] (inactive)]

Well, "report any problems" is a little vague. In Safari and Chrome, the file is still downloaded without any warning to the user, although in Chrome the file says: "Failed - No file".

I agree that "report any problems" is different from "navigate to an error page", but what is the expected behavior? I mean, how should the error be reported and should the file still be downloaded?

Comment 6

[Jessica Jong [:jessica] (inactive)]

Here [1] is where we return NS_ERROR_FILE_NOT_FOUND, that's why in EndPageLoad() [2], we display the internal error page.


[1] http://searchfox.org/mozilla-central/rev/2bcd258281da848311769281daf735601685de2d/uriloader/base/nsURILoader.cpp#554-565
[2] http://searchfox.org/mozilla-central/rev/2bcd258281da848311769281daf735601685de2d/docshell/base/nsDocShell.cpp#7741-7748

Comment 7

[PhistucK]

I think navigation can cause user data loss in a case that website did not intend to handle because it never expected a navigation (it expected a download). The way to report is up to you (and I agree that the Chrome way is unclear) and is a user interface issue.
I actually prefer the Safari way of downloading regardless of error. While it might be unintended, it might also be intended. The web developer has elected to make it a download operation. If that does not work as well as they intended, they will need to fix that.

Comment 8

[Simon Pieters [:zcorpan]]

I don't disagree that the spec can be clearer about expected behavior. Can you file an issue, please? https://github.com/whatwg/html/issues/new

Comment 9

[Olli Pettay [:smaug][[e-mail]]]

Safari and Chrome behavior sounds horrible, but not sure Gecko behavior is much better.
What kind of error do we normally show if download fails? Though, this is a bit different since the
download never really begins.
I guess we need some UI folks here to say what to do.

Comment 10

[Olli Pettay [:smaug][[e-mail]]]

Or, perhaps we need a spec change. If there is an error, fire error event on the <a> element?

Comment 11

[Olli Pettay [:smaug][[e-mail]]]

...and just don't download anything.

Comment 12

[Jessica Jong [:jessica] (inactive)]

Filed https://github.com/whatwg/html/issues/2775.

Comment 13

[Anne (:annevk)]

Firefox is no longer navigating so closing this. Specification issue still seems reasonable to address at some point though.